The present invention relates to a method and/or system for the alkylation of an olefin with an isoparaffin utilizing an acidic catalyst mixture. In another aspect, this invention relates to a method of reducing the concentration of organic fluorides in an alkylate product.
The use of catalytic alkylation processes to produce branched hydrocarbons having properties that are suitable for use as gasoline blending components is well known in the art. Generally, the alkylation of olefins by saturated hydrocarbons, such as isoparaffins, is accomplished by contacting the reactants with an acid catalyst to form a reaction mixture, settling the reaction mixture to separate the catalyst from the hydrocarbons, thereby forming a catalyst phase and a hydrocarbon phase. The hydrocarbon phase is further separated, for example, by fractionation, to recover the separate product streams. Normally, the hydrocarbon phase of the alkylation process contains hydrocarbons having five to ten carbon atoms per molecule. In order to have the highest quality gasoline blending stock, it is preferred for the alkylate hydrocarbons formed in the alkylation process to be highly branched and contain seven to nine carbon atoms per molecule.
It has long been known that recontacting an alkylate stream containing organic fluorides with hydrogen fluoride is an effective method to reduce the concentration of organic fluorides in such alkylate stream. In order to ensure adequate contact of the alkylate stream with the hydrogen fluoride, the industry has most typically chosen to use an eduction system in a separate recontacting vessel wherein hydrogen fluoride is educted into a flowing alkylate stream followed by separation of the alkylate from the hydrogen fluoride by gravity separation.
It is generally desirable to minimize the number of vessels containing hydrogen fluoride which are present in an alkylation unit. Therefore, development of an improved process and/or system for effectively recontacting alkylate with hydrogen fluoride without using an additional hydrogen fluoride containing vessel would be a significant contribution to the art.